ANALOG DEVICES AD712 Service Manual
Dual Precision, Low Cost,
A
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FEATURES
Enhanced replacement for LF412 and TL082
AC performance
Settles to ±0.01% in 1.0 μs
16 V/μs minimum slew rate (AD712J)
3 MHz minimum unity-gain bandwidth (AD712J)
DC performance
200 V/mV minimum open-loop gain (AD712K)
Surface mount available in tape and reel in
cordance with the EIA-481A standard
ac
MIL-STD-883B parts available
Single version available: AD711
Quad version: AD713
Available in PDIP, SOIC_N, and CERDIP packages
GENERAL DESCRIPTION
The AD712 is a high speed, precision, monolithic operational
amplifier offering high performance at very modest prices. Its
very low offset voltage and offset voltage drift are the results of
advanced laser wafer trimming technology. These performance
benefits allow the user to easily upgrade existing designs that
use older precision BiFETs and, in many cases, bipolar op amps.
The superior ac and dc performance of this op amp makes it
s
uitable for active filter applications. With a slew rate of 16 V/µs
and a settling time of 1 µs to ±0.01%, the AD712 is ideal as a
buffer for 12-bit digital-to-analog and analog-to-digital
converters and as a high speed integrator. The settling time is
unmatched by any similar IC amplifier.
The combination of excellent noise performance and low input
c
urrent also make the AD712 useful for photo diode preamps.
Common-mode rejection of 88 dB and open-loop gain of
400 V/mV ensure 12-bit performance even in high speed
unity-gain buffer circuits.
The AD712 is pinned out in a standard op amp configuration
nd is available in seven performance grades. The AD712J and
a
AD712K are rated over the commercial temperature range of
0°C to 70°C. The AD712A is rated over the industrial temperature range of −40°C to +85°C. The AD712S is rated over the
High Speed BiFET Op Amp
AD712
CONNECTION DIAGRAM
MPLIFIER NO. 1
OUTPUT
INVERTING
NONINVERTI NG
SOIC_
1
2
INPUT
3
INPUT
V–
4
AD712
Figure 1. 8-Lead PDIP (N-Suffix),
N (R-Suffix), and CERDIP (Q-Suffix)
military temperature range of −55°C to +125°C and is available
processed to MIL-STD-883B, Rev. C.
Extended reliability PLUS screening is available, specified over
t
he commercial and industrial temperature ranges. PLUS
screening includes 168-hour burn-in, in addition to other
environmental and physical tests.
The AD712 is available in 8-lead PDIP, SOIC_N, and CERDIP
pa
ckages.
PRODUCT HIGHLIGHTS
1. The AD712 offers excellent overall performance at very
competitive prices.
2. The Analog Devices, Inc. advanced processing technology
a
nd 100% testing guarantee a low input offset voltage (3 mV
maximum, J grade). Input offset voltage is specified in the
warmed-up condition.
3. Together with precision dc performance, the AD712 offers
exce
llent dynamic response. It settles to ±0.01% in 1 µs and
has a minimum slew rate of 16 V/µs. Thus, this device is ideal
for applications such as DAC and ADC buffers that require a
combination of superior ac and dc performance.
AMPLIFIER NO. 2
8
V+
OUTPUT
7
INVERTING
6
INPUT
NONINVERTI NG
5
INPUT
00823-001
Rev. G
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2006 Analog Devices, Inc. All rights reserved.
AD712
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TABLE OF CONTENTS
Features .............................................................................................. 1
Guarding...................................................................................... 14
Connection Diagram .......................................................................1
General Description......................................................................... 1
Product Highlights........................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Typical Performance Characteristics ............................................. 6
Settling Time................................................................................... 11
Optimizing Settling Time.......................................................... 11
Op Amp Settling Time—A Mathematical Model.................. 12
Applications Information .............................................................. 14
REVISION HISTORY
Digital-to-Analog Converter Applications ............................. 14
Noise Characteristics ................................................................. 15
Driving the Analog Input of an
Analog-to-Digital Converter .................................................... 15
Driving a Large Capacitive Load.............................................. 16
Filters ................................................................................................ 17
Active Filter Applications.......................................................... 17
Second-Order Low-Pass Filter.................................................. 17
9-Pole Chebychev Filter............................................................. 18
Outline Dimensions ....................................................................... 19
Ordering Guide .......................................................................... 20
8/06—Rev. F to Rev. G
Edits to Figure 1................................................................................ 1
Change to 9-Pole Chebychev Filter Section................................ 18
6/06—Rev. E to Rev. F
Updated Format..................................................................Universal
Deleted B, C, and T Models...............................................Universal
Changes to General Description .................................................... 1
Changes to Product Highlights....................................................... 1
Changes to Specifications Section.................................................. 3
Changes to Figure 43...................................................................... 15
7/02—Rev. D to Rev. E
Edits to Features.................................................................................1
9/01—Rev. C to Rev. D
Edits to Features.................................................................................1
Edits to General Description ...........................................................1
Edits to Connection Diagram..........................................................1
Edits to Ordering Guide...................................................................3
Deleted Metalization Photograph...................................................3
Edits to Absolute Maximum Ratings .............................................3
Edits to Figure 7.................................................................................9
Edits to Outline Dimensions......................................................... 15
Rev. G | Page 2 of 20
AD712
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SPECIFICATIONS
VS = ±15 V @ TA = 25°C, unless otherwise noted. Specifications in boldface are tested on all production units at final electrical test.
Results from those tests are used to calculate outgoing quality levels. All min and max specifications are guaranteed, although only those
shown in boldface are tested on all production units.
Table 1.
AD712J/A/S AD712K
Parameter Min Typ Max Min Typ Max Unit
INPUT OFFSET VOLTAGE1
Initial Offset
T
to T
MIN
to T
to T
MIN
MIN
MAX
to T
MAX
0.6/1.6/26 1.7/4.8/77 0.5 1.7 nA
MAX
0.3/0.7/11 0.6/1.6/26 0.1 0.6 nA
MAX
MAX
MAX
to T
MAX
to T
MAX
MIN
vs. Temp 7
vs. Supply
T
Long-Term Offset Stability 15 15 µV/month
INPUT BIAS CURRENT2
VCM = 0 V
VCM = 0 V @ T
VCM = ±10 V
INPUT OFFSET CURRENT
VCM = 0 V
VCM = 0 V @ T
MATCHING CHARACTERISTICS
Input Offset Voltage
T
MIN
Input Offset Voltage Drift
Input Bias Current
Crosstalk
@ f = 1 kHz 120 120 dB
@ f = 100 kHz 90 90 dB
FREQUENCY RESPONSE
Small Signal Bandwidth 3.0 4.0 3.4 4.0 MHz
Full Power Response 200 200 kHz
Slew Rate
Settling Time to 0.01% 1.0 1.2 1.0 1.2 µs
Total Harmonic Distortion 0.0003 0.0003 %
INPUT IMPEDANCE
Differential 3×1012||5.5 3×1012||5.5 Ω||pF
Common Mode 3×1012||5.5 3×1012||5.5 Ω||pF
INPUT VOLTAGE RANGE
Differential3 ±20 ±20 V
Common-Mode Voltage4 +14.5, −11.5 +14.5, −11.5 V
T
MIN
Common-Mode Rejection
Ratio
VCM = ±10 V
T
VCM = ±11 V
T
INPUT VOLTAGE NOISE 2 2 µV p-p
45 45 nV/√Hz
22 22 nV/√Hz
18 18 nV/√Hz
16 16 nV/√Hz
0.3
76
76/76/76
25
10
16
−V
76
76/76/76
70
70/70/70
+ 4
S
95
20
88
84
84
80
3/1/1
4/2/2
20/20/20
75
100
25
3/1/1
4/2/2
20/20/20
25
+VS − 2 −VS + 4
Rev. G | Page 3 of 20
0.2
7
80
80
20
5
18
80
80
76
74
100 dB
dB
20 V/µs
88 dB
84 dB
84 dB
80 dB
1.0
2.0
10
75
100
25
1.0
2.0
10
25
+VS − 2
mV
mV
V/°C
pA
pA
pA
mV
mV
µV/°C
pA
V
AD712
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AD712J/A/S AD712K
Parameter Min Typ Max Min Typ Max Unit
INPUT CURRENT NOISE 0.01 0.01 pA/√Hz
OPEN-LOOP GAIN
OUTPUT CHARACTERISTICS
Voltage
Current +25 +25 mA
POWER SUPPLY
Rated Performance ±15 ±15 V
Operating Range
Quiescent Current
1
Input offset voltage specifications are guaranteed after 5 minutes of operation at TA = 25°C.
2
Bias current specifications are guaranteed maximum at either input after 5 minutes of operation at TA = 25°C. For higher temperatures, the current doubles every 10°C.
3
Defined as voltage between inputs, such that neither exceeds ±10 V from ground.
4
Typically exceeding −14.1 V negative common-mode voltage on either input results in an output phase reversal.
150
100/100/100
+13, −12.5
±12/±12/±12
±4.5
+5.0
400
+13.9, −13.3
+13.8, −13.1
±18 ±4.5
+6.8
200
100
+13, −12.5
±12
+5.0
400 V/mV
V/mV
+13.9, −13.3 V
+13.8, −13.1 V
±18
+6.0
V
mA
Rev. G | Page 4 of 20
AD712
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ABSOLUTE MAXIMUM RATINGS
Table 2.
Parameter Rating
Supply Voltage ±18 V
Internal Power Dissipation
Input Voltage
Output Short-Circuit Duration Indefinite
Differential Input Voltage +VS and −V
Storage Temperature Range
Q-Suffix −65°C to +150°C
N-Suffix and R-Suffix −65°C to +125°C
Operating Temperature Range
AD712J/K 0°C to 70°C
AD712A −40°C to +85°C
AD712S −55°C to +125°C
Lead Temperature Range (Soldering 60 sec) 300°C
1
Thermal characteristics:
8-lead PDIP package: θJA = 165°C/W
8-lead CERDIP package: θJC = 22°C/W; θJA = 110°C/W
8-lead SOIC package: θJA = 100°C/W
2
For supply voltages less than ±18 V, the absolute maximum voltage is equal
to the supply voltage.
2
1
±18 V
S
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. G | Page 5 of 20
AD712
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TYPICAL PERFORMANCE CHARACTERISTICS
20
6
15
10
= 2kΩ
R
L
25°C
5
INPUT VOLTAGE SWING (V)
0
0510
SUPPLY VOLTAGE ± V
Figure 2. Input Voltage Swing vs. Supply Voltage
20
15
10
5
OUTPUT VOLTAGE SWING (V)
0
05
SUPPLY VOLTAGE ± V
+V
OUT
RL= 2kΩ
25°C
10 15 20
Figure 3. Output Voltage Swing vs. Supply Voltage
15 20
–V
OUT
5
4
3
QUIESCENT CURRENT (mA)
2
0 5 10 15 20
00823-002
SUPPLY VOLTAGE ± V
00823-005
Figure 5. Quiescent Current vs. Supply Voltage
6
10
7
10
8
= 0) (Amps)
10
CM
9
10
10
10
11
10
INPUT BIAS CURRENT (
12
10
–40 –20
00823-003
–60
0 20 40 60 80 100 120 140
TEMPERATURE (° C)
0823-006
Figure 6. Input Bias Current vs. Temperature
30
25
20
±15V SUPPLIES
15
10
OUTPUT VO LTAGE SW ING (V p -p)
5
0
10 100 1k 10k
LOAD RESISTANCE (Ω)
0823-004
Figure 4. Output Voltage Swing vs. Load Resistance
100
OUTPUT IMPEDANCE (Ω)
0.01
1.0
0.1
10
1k
Figure 7. Output Impedan
10k 100k 1M 10M
FREQUENCY (Hz)
Rev. G | Page 6 of 20
ce vs. Frequency
0823-007
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